Angular dependence of switching field distribution in (Co/Pd)n multilayer nanostructure arrays

Abstract

The characterization of switching field and its angular dependence has been tremendously useful in understanding the switching mechanisms in magnetic thin-films and patterned structures. However, the study of the distribution in switching fields (SFD) in arrays and its angular dependence is less common. In this work, we investigate this dependency in arrays of ðCo=PdÞ n multilayer nanostructures. Results from arrays with different element sizes and periodicities (pitches) are presented, and we found that, like the switching field, the SFD varies with applied field angle in a Stoner-Wohlfarth-like fashion. Furthermore, when the SFD is represented as a dependent variable of the switching field, we consistently found a linear relationship between the two, and that the slope depends on both array element size and pitch. In general, the SFD in arrays with the largest structures and the smallest pitch tends to have the strongest dependence on the switching field. For arrays with nanostructures of a fixed size, however, we found that SFD values are virtually identical, regardless of pitch, if the reversal field is applied near 45 with respect to the surface normal. That the minimum SFD depends only on the size of the elements and not the pitch has significant implications for the practical design of densely-packed magnetic nanostructure arrays. [http://dx.

Magnetic transition from dot to antidot regime in large area Co/Pd nanopatterned arrays with perpendicular magnetization

“…where A is the exchange stiffness coefficient. Its value for the Co/Pd system is usually taken between 1.5 × 10 -11 and 6 × 10 -11 J m −1 [40][41][42]. This estimation gives values of δ≈15 K 30 nm, in agreement with experimental results of Suharyadi et al [43].…”

Magnetic interactions in 2D and 3D arrays

“…On a macroscopic scale (averaging over many nanoscale elements) switching fields and their distributions have been measured using vibrating sample magnetometry (VSM) [Coffey et al, 2002], magneto-optic Kerr effect (MOKE) [Hu et al, 2005a], superconducting quantum interference device (SQUID) magnetometry [Goll and Bublat, 2013] and the anomalous Hall effect (AHE) [Lau and Liu, 2012]. Island to island variations in angular dependence are however easily overlooked using these macroscopic methods.…”